The isomerization of olefins is a well known process which is commonly performed utilizing elevated temperature and/or various mononuclear catalysts. Only recently has research in this area been directed toward photocatalysts and/or transition metal complexes. For example, U.S. Pat. No. 4,287,378 discloses the disproportionation, proportionation and/or isomerization of olefins utilizing electromagnetic radiation and mononuclear transition metal oxide catalysts such as magnesium oxide.
U.S. Pat. No. 4,332,654 is directed toward a process to form silylethers which utilizes an active catalyst formed from an irradiated transition metal carbonyl complex precursor. The complexes are polynuclear but are not mixed metal clusters.
U.S. Pat. No. 4,338,173 discloses a process for the catalytic isomerization of olefins which comprises exposing the combination of an olefin and a mononuclear transition metal complex, both in a gaseous state, to optical radiation.
Lastly, two journal articles, one by Knight, et al entitled "New Polynuclear Carbonyl Complexes Containing Iron with Cobalt or Rhodium" appearing in the Journal of American Chemical Society (1970), and the second by Hsieh, et al entitled "New Nickel-Cobalt, Nickel-Iron and Nickel-Manganese Polynuclear Carbonyl Complexes" appearing in the Journal of Organometallic Chemistry (1970), detail methods for the preparation of mixed metal clusters. Neither article discloses the utilization of light to initiate or increase catalytic activity of these mixed metal clusters.
Thus, while the art provides processes for the isomerization of olefins employing photocatalytic techniques, and also provides for the general synthesis of various metal clusters, the art has not disclosed any processes utilizing a photochemically activated polynuclear complex comprising iron and another transition metal and suitable ligands, wherein the iron atoms and the transition metal atoms are bonded directly together.